My introduction to Discworld happened when I bought a few second hand paperbacks on Portobello for under a pound in order to have something to read in the bus back from London. Later (well and truly addicted) I wenth through a few more when I was commuting regularly by train. But about a half of the Discworld novels I read as ebooks either on a Kindle, or a Kobo.

It has always been "frustrating" to have to click through the footnote links in Pratchetts ebooks. In a paper book (just like in Your comment) the footnotes really complete the train of thought. Often it's the whole pun of a joke. You know it's there. You damn well know it's worth it. On paper, all it takes is a glance down.

For me, the "Pratchett footnote" is therefore characterized as anything where "click to see a footnote" somehow breaks that payoff spell a bit.